Once, [Rabbi Chanoch] Teller was traveling with 16 of his  offspring .
.. while changing planes in Frankfurt, Teller noticed a German woman gaping. 'Are all of these your children?' the woman asked. 'From one wife?' 'Yes, God has blessed me with all these children,' the rabbi replied. 'Haven't you heard about the population problem?'the woman sniffed. 'How many more children do you want to have?' Rabbi Teller paused and looked the woman in the eye: 'About 6 million,' he said.